Hyunsik Jeong
I started my information security study from a university club called PLUS in POSTECH, South Korea. I mainly focused on reverse engineering and cryptography while playing CTFs with PLUS, and achieved numerous results including being one of the finalists of DEF CON CTF 4 years in a row. After the graduation, I got a Master’s degree from the graduate school of information security in KAIST, under supervision of Prof. Yongdae Kim and Prof. Insu Yun. Now, I work in S2W as a senior researcher, and play CTFs with perfect blue.
Work Experience
Senior Researcher
- Ransomware research - mainly on breaking cryptographic features
- Cryptographic analysis
- Offensive research
Software Engineer
- Mainly developed the blockchain called CodeChain (Link) in Rust
- Developed blockchain node APIs in TypeScript
- Studied various cryptographic methods used in blockchain technologies
Research Intern
- Interned at Netmarble AI Revolution Center (NARC)
- Studied reinforcement learning algorithms, including TRPO & PPO
Projects
Analysis of the Correctness of Qualcomm Hexagon Emulators and Decompilers via Differential Testing
For the master thesis. Analyzed Hexagon emulators (hexagon-sim from the Hexagon SDK, QEMU) and a decompiler (binja-hexagon) with the differential testing tool.
Verifiable Gacha System
A class project. Built a gacha platform with a VRF (verifiable random function). Users can fully access gacha logs, including verifiable random values. Still, only the server can generate random values.
Awards
1st place
Finalist
1st place
1st place
1st place
1st place
Finalist
1st place
1st place
1st place
1st place
1st place
1st place
Finalist
Finalist
Finalist
1st place
Finalist
Finalist
Finalist
Finalist
Finalist
26th place
10th place
Gold prize
Written Challenges
pbctf
Yet Another PRNG, Yet Another RSA, Binary Tree (Link)